This application claims the priority of German Application No. 10 2005 030 252.1, filed Jun. 29, 2005, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a multi-cylinder internal combustion engine for vehicles, having a plurality of air ducts leading to the cylinders and an associated engine control device situated in a housing.
A generic internal combustion engine is known from DE 44 03 219 A1, in which the air ducts leading to the cylinders and the associated engine control device are situated in a three-part housing. Two parts are designed as half-shells to which the contours of each of the air ducts, divided along a meridian surface, conform. The engine control device housing is situated in the third part. Additional sections of the air ducts also run therein.
It is also known from EP 0 674 100 A1 to combine the air ducts into a single unit, and to provide on the exterior thereof or in a cavity provided therein the switch box, i.e., the combination of all or at least a majority of the connecting plugs for the lines leading to the controllers, switches, actuators, sensors, and the like for the entire vehicle. More detailed information about the structural design of the unit and the switch box has not been published.
A disadvantage of internal combustion engines of the above-mentioned type is that the housing requires a relatively large amount of space and significant sealing measures, for example in the region of the half-shells. The housing contains a comparatively large number of individual parts, and is costly to manufacture in mass production.
There is therefore needed an internal combustion engine having the simplest and most compact design possible.
These and other needs are met by providing a multi-cylinder internal combustion engine for vehicles, having a plurality of air ducts leading to the cylinders and an associated engine control device situated in a housing. The air ducts are combined into a single unit, on the exterior of which the engine control device housing is situated on its lower part. A plurality of circuit boards are provided on the lower part, and the lower part and/or the circuit boards are adapted to the exterior shape of the air ducts so that the circuit boards are inclined with respect to one another.
The wall formed between the air ducts and the adjacent engine control device housing thus serves a double purpose. It forms a component of the engine control device housing and the air ducts, thereby simplifying the design and reducing the weight and the cost of the entire unit comprising the engine control device housing and the air ducts.
One advantage of the internal combustion engine according to the invention is that special sealing measures along the air ducts are omitted. The common use of the lower part of the engine control device housing as a part of the air ducts further economizes in weight and cost. The arrangement of the control device at the air ducts also results in a compact design.
A further advantage of the internal combustion engine according to the invention is the possibility of performing a complete function test of the internal combustion engine before it is installed in the vehicle.
In one embodiment of the invention, the circuit boards are electrically connected to one another by way of multi-strand ribbon cables. This results in a particularly simple and economical design.
In a further aspect of the invention, the circuit boards are detachably connected to the lower part of the housing. This provides a particularly simple possibility to replace the “heart” of the control device with a circuit board containing a microprocessor.
In another aspect of the invention, the circuit boards have a thermally-conducting connection with the lower part of the housing. An advantage of this embodiment is that special cooling measures for the control device may be omitted.
Further advantages and embodiments of the invention make use of connecting plugs for the circuit boards that are incorporated in the housing. Moreover, a lower part of the engine control device housing may simultaneously form a part of the air ducts.
These and other advantages and embodiments essentially serve to simplify the design and further reduce the manufacturing and maintenance costs.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.